1. Field of the Invention
The present invention is concerned with the adjustment of the headlights of a motor vehicle and in particular with remote adjustment to permit the headlight setting to be varied to compensate for changes in the attitude of the vehicle brought about by carrying different loads.
2. Description of the Prior Art
It is known to provide for remote manual or motorized adjustment of the setting of the vehicle headlights and more recently headlights had been specifically constructed with this aim in mind. Instead of the reflector being rigidly mounted in the headlight casing in relation to the front lens, the reflector is mounted for movement about three pivot points to permit horizontal and vertical adjustment. This gives the advantage that the adjusters are all encased within the housing of the headlight and are protected from dirt and corrosion.
There is little, if any, need to provide for remote horizontal adjustment, that is to say for moving the beam from left to right. Vertical adjustment to raise or lower the beam has been carried out by an actuator, such as an electrical motor, which is fitted to an opening in the outer casing of the headlight and has an output shaft which passes through the opening and is suitably connected to one of the pivot points.
The connection previously adopted between the output shaft of the actuator and the reflector has been a ball-and-socket joint. While permitting the reflector to be pulled in and out for vertical adjustment, the coupling also acts as a pivot so that the headlight may rotate about a vertical axis for the purpose of horizontal adjustment.
A ball-and-socket joint recessed within a housing presents difficulty in assembly. If the ball is a tight fit in the socket, then the force needed to push the ball into the socket can damage the delicate reflector, whereas if the ball is loose in the socket, then it can be dislodged in use.
This problem of gripping the ball of a ball-and-socket joint can be avoided by the use of a collar on the socket which can be tightened after insertion of the ball; but in the present case one cannot readily tighten a collar about the ball-and-socket joint after assembly because access to it is no longer possible through the opening in the casing.